Geraldine Ferraro, Walter Mondale's running mate in the 1984 presidential election, was featured on four Time magazine covers that year. Time's Amy Sullivan did a little archive digging and discovered that "in the twenty years following Ferraro's 1984 run, U.S. female politicians appeared on the cover of Time a grand total of four times."

Ferraro, who was the first woman to receive the nomination from a major political party for national office, died this past weekend, prompting Sullivan's investigation. Time's four female politicians since Ferraro's run were Janet Reno, Madeline Albright, Condoleeza Rice and Hillary Clinton. 1992 five women joined the U.S. Senate, but not one of them graced the cover of Time, Sullivan points out.

That small group of cover-worthy female politicians has grown slightly since 2006, a change which Sullivan attributes, in part, to Hillary Clinton's political success. Clinton and Sarah Palin may make up for nine of the 13 female politicians on Time covers in the past five years, but "it's progress that while Ruth Bader Ginsburg's arrival on the Supreme Court earned her no cover love, Sonia Sotomayor graced a cover upon her confirmation," she notes. "And while some critics may argue that putting Palin on the cover is elevating a politician of style instead of substance, that charge can't be leveled at Michael Scherer's cover story from last spring on Elizabeth Warren, Sheila Bair and Mary Schapiro."